New downtown home
Electric Power Board squeezes into tight Chattanooga site

By Candy McCampbell

An eight-story office building and parking garage in downtown Chattanooga are going up on a city block that had been virtually undevelopable because of hazardous waste on the site.

The $26 million project, scheduled for completion in summer 2005, will include the new headquarters building for Chattanooga's Electric Power Board and a 512-space parking garage for both employee and public use.

The general contractors are J & J Contractors Inc. and Raines Brothers Inc., the only local firms to bid on the job.

The project was bigger than either firm could handle individually, said Mike Lail, Raines Brothers president.

"We are both still hands-on general contractors," he added.

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Each structure has its own team of architect, engineer and site superintendent, though there is a single superintendent for the entire project, said Brent Collier, senior project manager for J&J.

The structures are only 8 in. apart, but they don't look like twins.

The office building, designed by Franklin & Associates Architects of Chattanooga, has a structural steel frame that will be finished with a granite exterior, chosen because the Electric Power Board plans to occupy the building for at least 50 years and wanted a permanent structure, said Joe Schultz, construction manager for the board.

The parking garage, also with eight levels, is made of post-tensioned poured-in-place concrete that allows for the longer structural spans, said architect Brian Clarke of Derthick, Henley & Wilkerson Architects of Chattanooga, which designed the garage.

The two buildings will "join" at access points at three levels.

Construction started in June 2003 but site work had been under way more than two years as the city of Chattanooga, the former owner, sought to remediate the environmental leftovers of former tenants, which included a dry-cleaning business and a service station.

SM&E Inc., working in conjunction with the Tennessee Department of Environment and Conservation's Division of Superfund, dealt with the petroleum hydrocarbon and chlorinated solvents, such as perchloroethene, or PCE, on the site, said Mark Harrison, Chattanooga manager for SM&E.

The company removed contaminated dirt from the site, dug monitoring wells to identify the area of damage and dug a system of 49 injection points under the buildings, he said.

The entire site also is covered with a rubber membrane seal - thicker than the rubber membrane used in many roofing applications.

"The EPB got the land as a 'clean' site," in a swap with the city for the power board's present location, Schultz said.

The delay over the environmental hazards added a year and half to the year that already had been scheduled for design, said Steve Clark, board vice president for reliability and maintenance.

One of the changes made during that time was the foundation design, said Jim Fischer, building project architect at Franklin & Associates, Architects. Instead of caissons, the foundation became 350 "mini piles" that extend to the bedrock that slopes toward the Tennessee River 10 blocks away, he said.

Limited available space influenced the footprint of the office building, which incorporates an existing small park near the entry, Fischer said. Crews are working around the trees there.

At the parking garage, the tight space called for a double loop access and exit, architect Clarke said.

But that's nothing like the squeeze for storage of construction materials.

"We have no space for materials," Lail said.

Qualico Steel Co. Inc., of Webb Ala., which has the structural and miscellaneous steel contract for the job, has to drop its loads at the J&J headquarters about five blocks away. Raines is also storing material at its headquarters.

About 1,200 tons of steel will be used in the buildings.

"The lack of laydown space requires us to schedule deliveries closely," Collier said.

The concrete for the garage will come in four pours per floor and the forming crew is scheduling one month for each floor, said Jeff Mills of forming contractor Harcon Inc. of Alpharetta, Ga. The 9,000 cu. yds. of concrete for the buildings is being delivered from a Sequatchie Concrete Service plant 2.5 mi. away.